CN108662026B - Seal for rolling bearing and rolling bearing - Google Patents
Seal for rolling bearing and rolling bearing Download PDFInfo
- Publication number
- CN108662026B CN108662026B CN201810257396.6A CN201810257396A CN108662026B CN 108662026 B CN108662026 B CN 108662026B CN 201810257396 A CN201810257396 A CN 201810257396A CN 108662026 B CN108662026 B CN 108662026B
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- Prior art keywords
- seal
- rolling bearing
- lip
- main lip
- core
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/72—Sealings
- F16C33/76—Sealings of ball or roller bearings
- F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
- F16C33/7803—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members suited for particular types of rolling bearings
- F16C33/7806—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members suited for particular types of rolling bearings for spherical roller bearings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/72—Sealings
- F16C33/76—Sealings of ball or roller bearings
- F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
- F16C33/7816—Details of the sealing or parts thereof, e.g. geometry, material
- F16C33/782—Details of the sealing or parts thereof, e.g. geometry, material of the sealing region
- F16C33/7823—Details of the sealing or parts thereof, e.g. geometry, material of the sealing region of sealing lips
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C19/00—Bearings with rolling contact, for exclusively rotary movement
- F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
- F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
- F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/72—Sealings
- F16C33/76—Sealings of ball or roller bearings
- F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
- F16C33/784—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted to a groove in the inner surface of the outer race and extending toward the inner race
- F16C33/7843—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted to a groove in the inner surface of the outer race and extending toward the inner race with a single annular sealing disc
- F16C33/7846—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted to a groove in the inner surface of the outer race and extending toward the inner race with a single annular sealing disc with a gap between the annular disc and the inner race
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/72—Sealings
- F16C33/76—Sealings of ball or roller bearings
- F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
- F16C33/784—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted to a groove in the inner surface of the outer race and extending toward the inner race
- F16C33/7843—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted to a groove in the inner surface of the outer race and extending toward the inner race with a single annular sealing disc
- F16C33/7853—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted to a groove in the inner surface of the outer race and extending toward the inner race with a single annular sealing disc with one or more sealing lips to contact the inner race
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/72—Sealings
- F16C33/76—Sealings of ball or roller bearings
- F16C33/78—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members
- F16C33/7869—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted with a cylindrical portion to the inner surface of the outer race and having a radial portion extending inward
- F16C33/7873—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted with a cylindrical portion to the inner surface of the outer race and having a radial portion extending inward with a single sealing ring of generally L-shaped cross-section
- F16C33/7876—Sealings of ball or roller bearings with a diaphragm, disc, or ring, with or without resilient members mounted with a cylindrical portion to the inner surface of the outer race and having a radial portion extending inward with a single sealing ring of generally L-shaped cross-section with sealing lips
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/16—Sealings between relatively-moving surfaces
- F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
- F16J15/3204—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip
- F16J15/3232—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip having two or more lips
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Rolling Contact Bearings (AREA)
- Sealing Of Bearings (AREA)
Abstract
In a seal for a rolling bearing, sliding resistance (bearing torque) is reduced while necessary sealing performance is maintained. A seal (6) for a rolling bearing is composed of a core (10) and an elastic member (11) covering the core, and a fitting section (12) is fixed to an outer ring so that a seal section (13) is in contact with an inner ring (2). An auxiliary lip (15) that does not contact the outer peripheral surface (2A) of the inner ring (2) protrudes outward of the seal section, and a main lip (16) that contacts the outer peripheral surface (2A) of the inner ring (2) protrudes inward of the inner peripheral side of the thick-walled section (13A). An annular groove (18) is provided between the main lip (16) and the thick portion (13A), and a thin flexible portion (19) is formed at the base of the main lip (16). The auxiliary lip (15) suppresses the entry of foreign matter and/or moisture, and reduces the external pressure acting on the main lip (16) to ensure the sealing performance of the main lip. A flexible portion (19) is formed at the base of the main lip (16) by the annular groove (18), and the sliding resistance of the main lip is reduced.
Description
Technical Field
The present invention relates to a seal for a rolling bearing that seals between an inner ring and an outer ring of the rolling bearing, and a rolling bearing to which the seal is attached.
Background
In a rolling bearing, in order to prevent foreign matter such as dust and/or moisture from entering from the outside and to prevent leakage of grease sealed inside the bearing, a rolling bearing with a seal including a seal for sealing between an inner ring and an outer ring is provided. In general, a rolling bearing with a seal is configured such that an annular seal comprising a rubber seal member reinforced by a core (inner core) is fixed to one of an inner ring and an outer ring, and a lip of the seal member is brought into contact with the other to seal a gap between the inner ring and the outer ring. Further, by designing the shape of the lip of the seal member, etc., it is possible to improve the sealing property and reduce the sliding resistance (the torque of the bearing).
For example, patent document 1 discloses a sealing device: a main lip contacting with the outer peripheral surface of the inner ring is formed on the inner side of the sealing member in the axial direction, and a non-contact portion forming a labyrinth seal is formed between the outer side and the inner ring. The sealing device alleviates external pressure acting on the main lip and prevents foreign matters from entering through a labyrinth seal of a non-contact part, and prevents partial abrasion of the main lip by making the main lip contact with the outer peripheral surface of the inner ring.
Patent document 1: japanese patent laid-open No. 2006 and 97851
However, in the sealing device described in patent document 1, since the main object is to cope with an external high pressure, the core extends to the vicinity of the tip end portion of the main lip, and the base portion of the main lip has a thick structure that is difficult to bend, the sliding resistance between the main lip and the inner ring increases, and the torque of the rolling bearing increases.
Disclosure of Invention
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a seal for a rolling bearing and a rolling bearing with a seal, which can reduce sliding resistance (bearing torque) while maintaining necessary sealing performance.
In order to solve the above-mentioned problems, the seal for a rolling bearing according to the invention of claim 1 is a ring-shaped seal for a rolling bearing which is fixed to an outer ring of a rolling bearing and seals between an inner ring and the outer ring,
comprises the following steps: an annular core extending between the inner race and the outer race, and an elastic member covering at least a portion of the core;
the elastic member has a seal portion that covers an inner surface and an outer surface of the inner circumferential portion of the core in an axial direction of the rolling bearing;
the seal portion has a thick-walled portion that is thicker than a portion covering the outer side surface of the core and covers the inner side surface of the core;
an inner peripheral portion of the seal portion includes: an auxiliary lip having a gap with respect to the outer peripheral surface of the inner ring and not in contact therewith, and a main lip in contact with the outer peripheral surface of the inner ring at a position axially inward of the auxiliary lip;
an annular groove that opens inward in the axial direction is provided between the thick portion of the seal portion and the main lip, and a thin flexible portion is formed at the base of the main lip.
The seal for a rolling bearing according to the invention of claim 2 is a ring-shaped seal for a rolling bearing which is fixed to an inner ring of a rolling bearing and seals between the inner ring and the outer ring, and is characterized in that,
comprises the following steps: an annular core extending between the inner race and the outer race, and an elastic member covering at least a portion of the core;
the elastic member has a seal portion that covers an inner side surface and an outer side surface of the outer peripheral portion of the core in an axial direction of the rolling bearing;
the seal portion has a thick-walled portion that is thicker than a portion covering the outer side surface of the core and covers the inner side surface of the core;
the outer peripheral portion of the seal portion is formed with: an auxiliary lip having a gap with respect to the inner peripheral surface of the outer ring so as not to be in contact therewith, and a main lip being in contact with the inner peripheral surface of the outer ring at a position axially inward of the auxiliary lip;
an annular groove that opens inward in the axial direction is provided between the thick portion of the seal portion and the main lip, and a thin flexible portion is formed at the base of the main lip.
The seal for a rolling bearing according to the invention of claim 3 is, in the configuration of claim 1 or 2, characterized in that: an inclination angle between an outer surface of the rolling bearing at the distal end portion of the auxiliary lip in the axial direction and an outer peripheral surface of the inner ring or an inner peripheral surface of the outer ring, which is not in contact with the auxiliary lip with a gap, is smaller than an inclination angle between an inner surface of the rolling bearing at the distal end portion of the auxiliary lip in the axial direction and an outer peripheral surface of the inner ring or an inner peripheral surface of the outer ring, which is not in contact with the auxiliary lip with a gap.
The seal for a rolling bearing according to the invention of claim 4 is the seal according to any one of claim 1 to claim 3, characterized in that: an inclination angle between a surface of a front end portion of the main lip on an inner side in an axial direction of the rolling bearing and an outer peripheral surface of the inner ring or an inner peripheral surface of the outer ring with which the main lip is in contact is smaller than an inclination angle between a surface of a front end portion of the main lip on an outer side in the axial direction of the rolling bearing and an outer peripheral surface of the inner ring or an inner peripheral surface of the outer ring with which the main lip is in contact.
The rolling bearing of the invention according to claim 5 is characterized in that: the seal for a rolling bearing according to any 1 of claims 1 to 4 is mounted.
According to the inventions of claims 1 and 2, the auxiliary lip suppresses entry of foreign matter such as dust and/or moisture between the inner ring and the outer ring, and reduces the external pressure acting on the main lip, thereby sealing the space between the inner ring and the outer ring by the main lip. By providing the annular groove between the thick portion of the seal portion and the main lip to form the thin flexible portion at the base portion of the main lip, the sliding resistance of the main lip can be reduced. By forming the non-contact auxiliary lip on the inner peripheral side (claim 1) or the outer peripheral side (claim 2) of the core, the rigidity thereof is increased, and stable sealing performance can be obtained. Further, by providing the thick portion on the inner side in the axial direction of the core, it is possible to improve the rigidity of the entire seal, to obtain stable sealing performance, and to improve the bondability of the elastic member to the core. Further, since the thick portion is provided continuously with the annular groove, the main lip can be prevented from being turned up and the grease inside the bearing can be prevented from being excessively adhered to the main lip.
According to the invention of claim 3, it is possible to effectively suppress entry of foreign matters such as dust and/or moisture from the outside.
According to the invention of claim 4, leakage of the grease held between the inner ring and the outer ring to the outside can be effectively suppressed.
According to the invention of claim 5, there can be provided the rolling bearing with seal including the seal according to any one of claims 1 to 4.
Drawings
Fig. 1 is a partial sectional view of a rolling bearing according to an embodiment of the present invention.
Fig. 2 is an enlarged sectional view of a seal of the rolling bearing of fig. 1.
Fig. 3 is an enlarged cross-sectional view of a seal portion which is an important part of the seal of fig. 2.
Fig. 4 is an explanatory view showing the inclination angles of the main lip and the auxiliary lip of the seal portion of fig. 3.
Fig. 5 is an enlarged cross-sectional view showing an important part of the seal of comparative examples 1 to 3 used in a torque measurement test and a dust test of the rolling bearing according to the present embodiment.
Fig. 6 is a schematic diagram of a testing device used in a torque measurement test of the rolling bearing of the present embodiment.
Fig. 7 is a graph showing the results of a torque measurement test of the rolling bearing of the present embodiment.
Fig. 8 is a graph showing the results of a dust test of the rolling bearing of the present embodiment.
Fig. 9 is a partial sectional view of a rolling bearing according to another embodiment of the present invention.
Description of the reference numerals
1: rolling bearing, 2: inner ring, 3: outer ring, 6: seal for rolling bearing, 10: core, 11: elastic member, 13: seal portion, 13A: thick portion, 15: auxiliary lip, 16: major lip, 18: annular groove, 19: flexible portion, H: gap, S: annular space, X: rotation axis, α 1, α 2, β 1, β 2: angle of inclination
Detailed Description
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The rolling bearing according to the present embodiment is described by way of example of a small-sized ball bearing having an outer diameter of about 10mm, which is used in a motor incorporated in information communication equipment such as a personal computer and/or a home electric appliance, a control motor of an automobile, a blower, a fan motor, and the like.
Fig. 1 is a partial sectional view of a rolling bearing 1 according to the present embodiment. In the following description, the direction of the rotation axis X of the rolling bearing 1 shown in fig. 1 is referred to as an axial direction, and a direction perpendicular to the axial direction is referred to as a radial direction. As shown in fig. 1, a rolling bearing 1 according to the present embodiment is a ball bearing with a seal, and includes: an inner ring 2; an outer ring 3; a plurality of rolling elements 4 (steel balls) accommodated between a raceway surface 2B formed on an outer circumferential surface 2A of the inner ring 2 and a raceway surface 3B formed on an inner circumferential surface 3A of the outer ring 3; and a cage 5 that holds the rolling elements 4 on the raceway surfaces 2B, 3B at a predetermined interval. In the rolling bearing 1, annular rolling bearing seals 6 and 6 (hereinafter, simply referred to as seals) for sealing an annular space S between the inner ring 2 and the outer ring 3 are provided at both axial end portions thereof so as to be fixed to the outer ring 3. An appropriate amount of grease is retained in the annular space S.
The outer peripheral surface 2A of the inner race 2 is formed as a cylindrical surface having a constant diameter except for the raceway surface 2B at the center in the axial direction. Annular seal grooves 8, 8 for attaching the seals 6, 6 are formed in the circumferential direction at both axial end portions of the inner peripheral surface 3A of the outer ring 3. The seal groove 8 is formed in a stepped shape having an axially inner small diameter portion 8A and an axially outer large diameter portion 8B, and an outer side wall of the large diameter portion 8B is formed as an inclined tapered surface portion 8C. Further, the inner peripheral edge portions 3C at both ends of the outer ring 3, that is, the outer portions of the seal grooves 8, 8 in the axial direction are formed to have a larger diameter than the inner peripheral surface 3A. Since the seals 6, 6 provided at both ends of the rolling bearing 1 have the same structure, only one (the right seal 6 in fig. 1) will be described in detail below.
Referring to fig. 2, the seal 6 is composed of a metal core 10 and a rubber elastic member 11 covering at least a part of the core 10.
The core 10 is an annular member extending in the radial direction between the outer peripheral surface 2A of the inner ring 2 and the inner peripheral surface 3A of the outer ring 3. The inner peripheral portion of the core 10 extends to the vicinity of the outer peripheral surface 2A of the inner ring 2, and the outer peripheral portion extends to a position substantially reaching the inner peripheral surface 3A of the outer ring 3. The outer peripheral portion of the core 10 is bent at a right angle to the inside of the rolling bearing 1 to form a cylindrical portion 10A along the inner peripheral surface 3A of the outer ring 3. The core 10 is inserted into the elastic member 11, and the periphery thereof is covered with the elastic member 11, but is exposed to the outside from the inner peripheral surface of the cylindrical portion 10A to a region near the inner peripheral portion of the end surface facing the inside of the rolling bearing 1. The core 10 reinforces the elastic member 11 and maintains the shape of the sealing member 6 against an external force.
The elastic member 11 of the seal 6 is an annular member formed integrally with: an outer peripheral fitting portion 12 that covers the outer peripheral side of the core 10, fits into the seal groove 8 of the outer ring 3, and is fixed to the outer ring 3; an inner peripheral side seal portion 13 which covers the inner peripheral side of the core 10 and has a portion (a main lip 16 described later) in contact with the outer peripheral surface 2A of the inner ring 2; and an intermediate portion 14 therebetween. The fitting portion 12 has: a small diameter portion 8A fitted to the seal groove 8 of the outer ring 3 and a stepped portion 12A of the large diameter portion 8B, an inclined portion 12B fitted to the tapered portion 8C, and an inclined surface 12C formed between the stepped portion 12A and the inclined portion 12B; fitted into the inner surface of the seal groove 8 to fix the seal 6 to the outer ring 3. The intermediate portion 14 covers the axial outer side of the core 10, and is continuous with the fitting portion 12 and the seal portion 13.
Next, the seal portion 13 of the elastic member 11 will be described with reference to fig. 3 and 4.
The seal portion 13 is formed to cover the inner surface and the outer surface of the inner circumferential portion of the core 10 in the axial direction and face the outer circumferential surface 2A of the inner ring 2. The seal portion 13 has a thick portion 13A that is thicker than a portion covering the outer side surface of the core 10 in the axial direction and covers the inner side surface of the inner peripheral portion of the core 10 in the axial direction. The outer peripheral surface of the thick portion 13A is formed as a tapered surface 13B having a large diameter on the core 10 side. An auxiliary lip 15 and a main lip 16 that protrude toward the outer peripheral surface 2A of the inner ring 2 are formed on the inner peripheral portion of the seal portion 13 on the axially outer side and the axially inner side, respectively, and an inner peripheral groove 17 that faces the outer peripheral surface 2A of the inner ring 2 is formed between the auxiliary lip 15 and the main lip 16.
The tip end of the auxiliary lip 15 is not in contact with the outer peripheral surface 2A of the inner ring 2 with a slight gap H. On the other hand, the tip end portion of the main lip 16 contacts the outer peripheral surface 2A of the inner ring 2 with a predetermined interference. The tip portions of the auxiliary lip 15 and the main lip 16 are formed in a V-shape in cross section in which the inner side and the outer side in the axial direction are inclined. The tip end portion of the auxiliary lip 15 is disposed at a position radially inward of the core 10, that is, at a position overlapping the core 10 in the axial direction. The tip end of the main lip 16 is formed on the axially inner side of the core 10, i.e., on the radially inner side of the thick portion 13A.
As shown in fig. 4(a), an inclination angle α 1 between the axially outer surface of the auxiliary lip 15 and the outer peripheral surface 2A of the inner ring 2 is smaller than an inclination angle β 1 between the axially inner surface of the auxiliary lip 15 and the outer peripheral surface 2A of the inner ring 2. As shown in fig. 4(B), an inclination angle β 2 between the axially inner surface of the main lip 16 and the outer peripheral surface 2A of the inner ring 2 is smaller than an inclination angle α 2 between the axially outer surface of the main lip 16 and the outer peripheral surface 2A of the inner ring 2.
As shown in fig. 3, an annular groove 18 is formed between the thick portion 13A of the seal portion 13 and the main lip 16. The annular groove 18 is disposed radially inward of the core 10 of the seal portion 13, opens axially inward of the seal portion 13, and extends to a depth reaching radially inward of the core 10. The annular groove 18 has two side walls formed in a conical shape and has a width that decreases toward the bottom. Accordingly, a thin flexible portion 19 extending from the auxiliary lip 15 side to the inside in the axial direction is formed at the base of the main lip 16 by the inner peripheral groove 17 and the annular groove 18 between the auxiliary lip 15 and the main lip 16. The flexible portion 19 is included in the base portion of the main lip 16, and is a thin portion thinner in the radial direction than the thickness from the annular groove 18 to the tip end portion of the main lip 16. In the illustrated example, the main lip 16 is extended to a position corresponding to the inner end surface of the thick portion 13A in the axial direction, but may be extended to a position beyond or not beyond this position.
In the main lip 16 extending axially inward from the main body of the seal portion 13 in this manner, the distal end portion connected to the main body of the seal portion 13 via the flexible portion 19 is in contact with the outer peripheral surface 2A of the inner ring 2 having no step from the radial direction. According to the seal 6 configured as described above, the contact pressure with the inner ring 2 is reduced to reduce the sliding resistance, thereby reducing the torque of the inner ring 2.
In addition, although the corners of the cross-sectional shape of the elastic member 11 of the seal 6 shown in the drawings are not chamfered or rounded (R), the corners may be chamfered or rounded (R) as appropriate.
Next, the operation of the rolling bearing 1 according to the present embodiment configured as described above will be described.
The rolling bearing 1 supports the inner ring 2 and the outer ring 3 so as to be rotatable relative to each other, and reduces rotational resistance (torque) by rolling of the rolling elements 4. The annular space S between the inner ring 2 and the outer ring 3 is sealed by the seals 6 and 6, thereby preventing foreign matter such as dust and/or moisture from entering the annular space S from the outside and preventing grease held in the annular space S from leaking to the outside.
At this time, the seal 6 suppresses entry of foreign matter from the outside and reduces the external pressure acting on the main lip 16 by the auxiliary lip 15 having the minute gap H and not contacting the inner ring 2. As shown in fig. 4 a, the auxiliary lip 15 makes the inclination angle α 1 between the axially outer surface and the outer peripheral surface 2A of the inner ring 2 smaller than the inclination angle β 1 between the axially inner surface and the outer peripheral surface 2A of the inner ring 2, so that foreign substances and/or liquid are likely to stay on the outer side where the inclination angle is small (α 1 < β 1), and entry of foreign substances such as dust and/or moisture from the outside can be effectively suppressed. Further, since the auxiliary lip 15 is disposed radially inward of the core 10 and the core 10 extends to the vicinity of the auxiliary lip 15, the core 10 can have increased rigidity and can provide stable sealing performance.
On the other hand, the main lip 16 is provided on the thick portion 13A side, but by providing the annular groove 18 between the main lip and the thick portion 13A and forming the thin flexible portion 19 at the base portion of the main lip 16, the contact pressure with the inner ring 2 can be reduced to reduce the sliding resistance and the torque of the inner ring 2. At this time, as described above, the auxiliary lip 15 suppresses entry of foreign matter such as dust and/or moisture from the outside and reduces the external pressure acting on the main lip 16, so that the main lip 16 can secure necessary sealing performance. As shown in fig. 4B, the main lip 16 makes the inclination angle β 2 between the axially inner surface and the outer peripheral surface 2A of the inner ring 2 smaller than the inclination angle α 2 between the axially outer surface and the outer peripheral surface 2A of the inner ring 2, so that liquid or the like is likely to stay on the inner side where the inclination angle is small (β 2 < α 2), and therefore leakage of the grease held in the annular space S can be effectively suppressed.
The main lip 16 has increased flexibility by forming a thin flexible portion 19 by providing an annular groove 18 between the main lip and the thick portion 13A, but the rigidity of the entire seal 6 is increased by the thick portion 13A provided on the axially inner side of the seal portion 13, and therefore stable sealing performance can be maintained. Further, since the thick portion 13A is provided continuously with the annular groove 18, the amount of deflection of the main lip 16 can be restricted by the thick portion 13A, tilting of the main lip 16 can be prevented, and excessive adhesion of grease in the annular space S to the main lip 16 can be prevented. Further, in the case where the rolling bearing 1 is a small-sized bearing having an outer diameter of about 10mm, the thickness of the core 10 and the thickness of the elastic member 11 are considerably reduced, but since the thick portion 13A is provided on the inner side in the axial direction of the seal portion 13, the bondability between the core 10 and the elastic member 11 can be ensured, and therefore the seal 6 can be easily manufactured by press forming or the like.
Next, a torque measurement test and a dust test, which are performed to compare the sealing performance of the rolling bearing 1 of the above embodiment with that of the rolling bearings (comparative examples 1 to 3) to which the seals shown in fig. 5(a) to (C) are respectively attached, will be described. Note that, since the seals 20A to 20C shown in fig. 5(a) to (C) differ from the seal 6 of the present embodiment only in the shape of the inner peripheral portion, the same reference numerals are appropriately used for corresponding portions in the following description, and the description of the same portions will be omitted.
A seal 20A shown in fig. 5(a) is a standard seal to be mounted on a rolling bearing, and has a cross-sectional shape in which an annular groove 23 is formed on the outer side in the axial direction of a seal portion 22 disposed on the inner side in the axial direction with respect to the core 10 and is convexly curved toward the inner side in the axial direction. The seal portion 22 has only a single main lip 24 that contacts the outer peripheral surface 2A of the inner ring 2, and does not have the auxiliary lip 15. The main lip 24 has a larger contact width in the axial direction with the outer peripheral surface 2A of the inner ring 2 than the main lip 16 of the seal 6 of the present embodiment. The distance between the inner peripheral edge of the core 10 and the outer peripheral surface 2A of the inner ring 2 is slightly larger than the seal 6 of the present embodiment. Hereinafter, a rolling bearing in which the seal 20A shown in fig. 5(a) is mounted on both sides in the axial direction will be referred to as "comparative example 1".
In the seal 20B shown in fig. 5(B), the thick portion 13A of the seal portion 13 does not have the annular groove 18 on the axially inner side with respect to the seal 6 of the present embodiment, and therefore the main lip 16 does not have the thin flexible portion 19. Hereinafter, a rolling bearing in which the seal 20B shown in fig. 5(B) is mounted on both sides in the axial direction will be referred to as "comparative example 2".
In the seal 20C shown in fig. 5(C), the thick portion 13A of the seal portion 13 does not have the annular groove 18 on the inner side in the axial direction with respect to the seal 6 of the present embodiment, and instead, an annular groove 25 is formed on the outer side in the axial direction of the seal portion 13. Therefore, the main lip 16 that is in contact with the outer peripheral surface 2A of the inner ring 2 does not have the thin flexible portion 19, and instead, the auxiliary lip 15 that is not in contact with the outer peripheral surface 2A of the inner ring 2 has the thin flexible portion 26. Hereinafter, a rolling bearing in which the seal 20C shown in fig. 5(C) is mounted on both sides in the axial direction will be referred to as "comparative example 3".
The rolling bearing 1 of the present embodiment and comparative examples 1 to 3 were deep groove ball bearings having an inner diameter of 3mm and an outer diameter of 8mm, and the following torque measurement test and dust test were performed for evaluating the sealing performance.
(1) Torque measurement test
The torque of each bearing was measured for the rolling bearing 1 and comparative examples 1 to 3 using a measuring device M shown in fig. 6. As shown in fig. 6, the measuring apparatus M was configured such that 2 bearings W to be tested were set to 1 set, the outer ring of each bearing W was inserted and fitted into the inner peripheries of both end portions of the cylindrical housing H, the shaft S rotationally driven by the drive motor was inserted and fitted into the inner ring, and the shaft S was rotated at 10000rpm in a state where a preload Fa of F2N was applied to the inner ring. Then, a tangential force acting on the housing H attached to the outer ring was measured by a measuring machine R using a load cell, and based on the measured tangential force, the torque of each of the 2 bearings was calculated. The calculated torque of 2 bearings was divided by 2 to obtain the torque of 1 bearing. The torque was measured under a normal temperature and normal humidity environment, and an average value of 10 measurements for each bearing was calculated, and the torque was represented by a relative value using comparative example 1 (standard) as a reference (100). The torque is preferably lower than that of comparative example 1, that is, lower than 100.
The measurement results of the torque are shown in fig. 7.
(2) Dust test
In the dust test, the rolling bearing 1 of the present embodiment and comparative examples 1 to 3 were suspended in a dryer by a rope, and dust was circulated in the dryer for 1 hour by a fan motor. Powder 1 for JIS test (8 types of kanto soil (Seki imperial ローム) in accordance with JIS Z8901) was used for the dust. The Andrew values before and after the dust test were measured by an Andrew measuring instrument (アンデロンメータ), and acoustic evaluation based on the amount of increase in the Andrew values before and after the dust test was performed. In this case, the smaller the increase in the anderson value, the smaller the degree of coarsening of the seat surface due to the dust, that is, the smaller the dust penetration. The acoustic evaluation of the dust test is performed in the M band (300 to 1800Hz) and the H band (1800 to 10000 Hz). The results of the dust test are shown in fig. 8.
The following is apparent from the results of the torque measurement test shown in fig. 7 and the results of the dust test shown in fig. 8. The rolling bearing 1 of the present embodiment has a lower torque and a lower increase in the anderson value (less dust) than the rolling bearing of comparative example 1 (standard product). In comparative example 2, the increase in the andersu value was low (less dust was introduced) but the torque was high as compared with comparative example 1. In comparative example 3, the torque was lower than that in comparative example 1, but the increase in andersu value was high (the amount of dust entering was large).
In the rolling bearing 1 of the present embodiment, the annular groove 18 is provided between the main lip 16 and the thick portion 13A to form the flexible portion 19, so that the contact pressure of the main lip 16 with respect to the outer peripheral surface 2A of the inner ring 2 can be reduced, and the sliding resistance can be reduced. Therefore, the torque can be suppressed to be low. Further, since the annular groove 25 as in the seal 20C of comparative example 3 is not provided on the auxiliary lip 15 side, the rigidity of the auxiliary lip can be secured, and the entry of dust can be suppressed.
In the above embodiment, the case where the seal 6 is fixed to the outer ring 3 is described, but the present invention is not limited to this, and the present invention can be similarly applied to the case where the seal 6 is fixed to the inner ring 2 as shown in fig. 9. In this case, the seal groove 8 for fixing the seal 6 is provided in the inner ring 2, the inner peripheral surface 3A of the outer ring 3 is a cylindrical surface, the fitting portion 12 of the seal 6 is formed on the inner peripheral side, the seal portion 13 is formed on the outer peripheral side, and the auxiliary lip 15 is formed in contact with the main lip 16 with a small gap in the inner peripheral surface 3A of the outer ring 3. In fig. 9, corresponding parts are given the same reference numerals as in the embodiment shown in fig. 1 to 4.
In the above-described embodiment, the ball bearing is described as an example, but the present invention is not limited to this, and can be similarly applied to other rolling bearings such as a roller bearing.
Claims (7)
1. A seal for a rolling bearing, which is annular and fixed to an outer ring of the rolling bearing, and which seals between the inner ring and the outer ring, the seal comprising:
an annular core extending between the inner and outer races and an elastic member covering at least a portion of the core,
the elastic member has a seal portion that covers an inner surface and an outer surface of the inner circumferential portion of the core in an axial direction of the rolling bearing,
the seal portion has a thick-walled portion that is thicker than a portion covering the outer side surface of the core and covers the inner side surface of the core,
an auxiliary lip that is not in contact with the outer circumferential surface of the inner ring with a gap therebetween and a main lip that is in contact with the outer circumferential surface of the inner ring on the axially inner side of the auxiliary lip are formed on the inner circumferential portion of the seal portion,
an inner peripheral groove is provided between the auxiliary lip and the main lip,
an annular groove that opens inward in the axial direction is provided between the thick portion of the seal portion and the main lip, a thin flexible portion is formed at the base of the main lip,
the flexible portion is disposed between the inner circumferential groove and the annular groove.
2. The seal for rolling bearing according to claim 1, characterized in that:
an inclination angle between a surface of the front end portion of the auxiliary lip on the outer side in the axial direction of the rolling bearing and an outer peripheral surface of the inner ring with a gap without contact with the auxiliary lip is smaller than an inclination angle between a surface of the front end portion of the auxiliary lip on the inner side in the axial direction of the rolling bearing and an outer peripheral surface of the inner ring with a gap without contact with the auxiliary lip.
3. The seal for rolling bearing according to claim 1 or 2, characterized in that:
an inclination angle between a surface of the front end portion of the main lip on an inner side in the axial direction of the rolling bearing and an outer peripheral surface of the inner ring with which the main lip is in contact is smaller than an inclination angle between a surface of the front end portion of the main lip on an outer side in the axial direction of the rolling bearing and an outer peripheral surface of the inner ring with which the main lip is in contact.
4. A seal for a rolling bearing, which is annular and fixed to an inner ring of the rolling bearing to seal between the inner ring and the outer ring, comprising:
an annular core extending between the inner and outer races and an elastic member covering at least a portion of the core,
the elastic member has a seal portion that covers an inner side surface and an outer side surface of the outer peripheral portion of the core in an axial direction of the rolling bearing,
the seal portion has a thick-walled portion that is thicker than a portion covering the outer side surface of the core and covers the inner side surface of the core,
an auxiliary lip that is not in contact with the inner peripheral surface of the outer ring with a gap therebetween and a main lip that is in contact with the inner peripheral surface of the outer ring on the axially inner side of the auxiliary lip are formed on the outer peripheral portion of the seal portion,
an inner peripheral groove is provided between the auxiliary lip and the main lip,
an annular groove that opens inward in the axial direction is provided between the thick portion of the seal portion and the main lip, a thin flexible portion is formed at the base of the main lip,
the flexible portion is disposed between the inner circumferential groove and the annular groove.
5. The seal for rolling bearing according to claim 4, characterized in that:
an inclination angle between an outer surface of a tip end portion of the auxiliary lip in the axial direction of the rolling bearing and an inner peripheral surface of the outer ring with which the auxiliary lip is not in contact with the outer ring with a gap therebetween is smaller than an inclination angle between an inner surface of a tip end portion of the auxiliary lip in the axial direction of the rolling bearing and an inner peripheral surface of the outer ring with which the auxiliary lip is not in contact with the outer ring with a gap therebetween.
6. The seal for rolling bearing according to claim 4 or 5, characterized in that:
an inclination angle between a surface of a front end portion of the main lip on an inner side in an axial direction of the rolling bearing and an inner peripheral surface of the outer ring with which the main lip is in contact is smaller than an inclination angle between a surface of the front end portion of the main lip on an outer side in the axial direction of the rolling bearing and an inner peripheral surface of the outer ring with which the main lip is in contact.
7. A rolling bearing characterized in that:
a seal for a rolling bearing according to any 1 of claims 1 to 6 is provided.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017063672 | 2017-03-28 | ||
| JP2017-063672 | 2017-03-28 | ||
| JP2017-246398 | 2017-12-22 | ||
| JP2017246398A JP7112201B2 (en) | 2017-03-28 | 2017-12-22 | Rolling bearing seals and rolling bearings |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108662026A CN108662026A (en) | 2018-10-16 |
| CN108662026B true CN108662026B (en) | 2021-07-30 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810257396.6A Active CN108662026B (en) | 2017-03-28 | 2018-03-27 | Seal for rolling bearing and rolling bearing |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US10458477B2 (en) |
| CN (1) | CN108662026B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6986050B2 (en) * | 2019-06-21 | 2021-12-22 | ミネベアミツミ株式会社 | Bearing monitoring device, bearing monitoring method |
| JP7281422B2 (en) * | 2020-01-15 | 2023-05-25 | 株式会社シマノ | fishing reel |
| IT202000015814A1 (en) * | 2020-07-01 | 2022-01-01 | Skf Ab | SEAL FOR BEARING UNIT |
| IT202000024160A1 (en) * | 2020-10-14 | 2022-04-14 | Skf Ab | SEAL FOR BEARING UNITS WITH OPTIMIZED ANCHORAGE |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005163900A (en) * | 2003-12-02 | 2005-06-23 | Koyo Seiko Co Ltd | Rolling bearing |
| ITTO20040340A1 (en) * | 2004-05-21 | 2004-08-21 | Skf Ab | SEALING DEVICE FOR A ROLLING BEARING |
| JP4539270B2 (en) | 2004-09-30 | 2010-09-08 | 株式会社ジェイテクト | Rolling bearing seal device and rolling bearing device |
| JP2008151164A (en) * | 2006-12-14 | 2008-07-03 | Nsk Ltd | Seal for bearing, bearing and forming die |
| FR2926345B1 (en) * | 2008-01-16 | 2010-03-26 | Skf Ab | SEAL JOINT AND BEARING BEARING COMPRISING SUCH A SEAL |
| JP2010138931A (en) * | 2008-12-09 | 2010-06-24 | Ntn Corp | Sealed rolling bearing |
| JP5471265B2 (en) * | 2009-10-07 | 2014-04-16 | 日本精工株式会社 | Rolling bearing with seal ring |
| JP2011085247A (en) * | 2009-10-19 | 2011-04-28 | Thk Co Ltd | Motion guiding device |
| JP5969267B2 (en) * | 2012-05-24 | 2016-08-17 | Ntn株式会社 | Bearing for outer ring rotation |
| DE102012219497A1 (en) * | 2012-10-25 | 2014-04-30 | Schaeffler Technologies Gmbh & Co. Kg | Sealing element for a rolling bearing |
| JP6331754B2 (en) * | 2013-07-09 | 2018-05-30 | 日本精工株式会社 | Ball bearing with seal ring |
| CN204458821U (en) * | 2015-02-09 | 2015-07-08 | 宁波市镇海银球轴承有限公司 | Novel double-row deep groove ball bearing |
-
2018
- 2018-03-23 US US15/934,220 patent/US10458477B2/en active Active
- 2018-03-27 CN CN201810257396.6A patent/CN108662026B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN108662026A (en) | 2018-10-16 |
| US20180283455A1 (en) | 2018-10-04 |
| US10458477B2 (en) | 2019-10-29 |
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